Seal of Testing Assurance

The Seal of Testing Assurance (STA) is a program of the U.S. Composting Council, an organization that promotes the use of sewage sludge in compost. The STA program, developed in 2000, requires regular testing of compost products by "certified" labs. The testing is relatively minimal and the standards are designed to allow for certification of products containing sewage sludge.

According to USCC:
 * "The science behind the development of the STA Program and the various tests that are used is contained in ‘Test Methods for the Examination of Composting & Compost’ (‘TMECC’). This publication includes a suite of physical, chemical and biological tests. These were selected to help both compost producer and purchaser to determine if the compost they are considering is suitable for the use that they are planning, and to help them compare various compost products using a testing program that can be performed by a group of independent, certified labs across the country and in Canada."

TMECC, and thus the standards of the STA program, were developed in a process that was initiated by Proctor and Gamble in 1995. Ultimately, the USDA and the U.S. Composting Council's Composting Council Research and Education Foundation (CCREF) worked together to finalize and publish the standards.

Elements Tested in STA
Composts in the STA program are tested for the following:
 * pH
 * soluble salts
 * nutrient content (total N, P2O5, K2O, Ca, Mg)
 * moisture content
 * organic matter content
 * bioassay (maturity)
 * stability (respirometry)
 * particle size (report only)
 * pathogen (Fecal Coliform or Salmonella)
 * trace metals: arsenic, cadmium, chromium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc.

Additionally, "any and all testing required by applicable State and/or Federal regulation (e.g., pathogens, heavy metals, pesticides, inerts, etc.) to assure public health/safety and environmental protection must be completed at the frequency so regulated."

Related SourceWatch articles

 * Biosolids
 * Sewage sludge
 * Food Rights Network
 * U.S. Composting Council